Casio fx-39

Last updated
Casio fx-39 Scientific Calculator
Casio fx-39 Scentific Calculator.jpg
Casio fx-39
Type Scientific
Manufacturer Casio
Introduced1978
Predecessorfx-29
Calculator
Entry mode Infix
Precision8 digits mantissa, ±99 exponent
Display type vacuum fluorescent display (VFD)
Display size8 Characters +1 for sign
Programming
Programming language(s)Not programmable
Other
Power supply2×AA or AC adapter
Power consumption0.75W
Weight177g, 6.3 oz (including batteries)
Dimensions15.2x8.4x2.25 cm, 6"×3+3/8"x7/8"

The fx-39 is a scientific calculator manufactured by Casio released in 1978 [1] and is one of several models to share the same physical design format.

Contents

Display

The unit features a blue-green, light-emitting vacuum fluorescent display (VFD). The display device itself has 9 seven segment digits, 8 of which are used for numeric output, the 9th being for the minus sign or to accommodate a space for 6+2 scientific notation. Although only capable of displaying 6 figures when using scientific notation, the calculator works internally to 8. A vacuum fluorescent display (VFD) is a display device used commonly on consumer-electronics equipment such as video cassette recorders, car radios, and microwave ovens. A VFD operates on the principle of cathodoluminescence, roughly similar to a cathode ray tube, but operating at much lower voltages.

Design

The physical design was an impressive step forward from previous, more boxy, models such as the fx-19; sporting three rows of scientific function keys, a stylish metal fascia and rather novel four-position slide switch on the right side. This switch is used to select the trigonometric mode (Degrees, Radians or Gradians) or statistical operation. The unit is pocket sized and originally came with a black plastic slip cover to protect it.

Features

As well as the four standard functions and a memory, it has square root, square, change sign, reciprocal, factorial, pi, powers, trigonometry, common and natural logarithms as well as statistics and the following:

Casio introduced a number of improvements which were to be continued into subsequent models:

sinh x = (e^x – e^-x)/2 and

cosh x = (e^x + e^-x)/2.

Power

The unit is powered by 2 AA cells held within the battery compartment, which occupies a cavity behind the display. Alternatively, it can be powered using the Casio mains adapter through a socket on the top of the unit.

References

  1. "Vintage Technology Info". Archived from the original on 2019-06-20. Retrieved 2014-03-11.