**Casio AL-8 & family models**

Casio Computer Co. Ltd. was very innovative in calculator development and produced these novel designs:

- The Casio
*AL-8*and Casio*AL-10*were the first hand-held calculators to accept and display fractions, and can also operate on and display in hours, minutes, and seconds. - The Casio
*AL-8S*can operate on and display fractions and also dates of the year.

**Casio AL-8**

**Distinctive features:** Accepts and displays fractions and time.

**Technical details:**Display is 8 digits, green fluorescent.

4-function, %, memory, square root, fractions, hours minutes seconds, and Standard Deviation.

3v (2x AA batteries).

80 x 138 x 23 mm (3.1" x 5.4" x 0.9").

1975.

Price in the U.S.A. in august 1976 US$24.95^{[1]}.

Made in Japan.

Displaying the fraction 3/4.

Note the slide switch on the right to select the mode, including fractions, hours minutes seconds, and standard deviation.

**Casio AL-10**

**Distinctive features:** Accepts and displays fractions and time.

**Technical details:**Display is 10 digits, green fluorescent.

4-function, %, memory, square root, fractions, hours minutes seconds, and Standard Deviation.

3v (2x AA batteries).

80 x 138 x 23 mm (3.1" x 5.4" x 0.9").

1975.

Made in Japan.

Displaying the fraction

3 7/16.

The circuit board of the Casio *AL-10*, showing the vacuum fluorescent display in a single tube, the chip made by NEC, and the voltage converter on a small board (to produce the driving voltage
for the display).

**Casio AL-8S**

**Distinctive features:** Accepts and displays fractions, time, and dates.

**Technical details:**Display is 8 digits, green fluorescent.

4-function, %, memory, square root, fractions, date.

3v (2x AA batteries).

81 x 142 x 22 mm (3.2" x 5.6" x 0.9").

Made in Japan.

To add and subtract dates, and to find the day of the week of a date, the "DATE" button is used. In this case we wanted to find out the date and the day of the week 16 days after Christmas day 1978
(25th December 1978).

Enter 78 for the year, press "DATE", and the display shows 1978, showing that it defaults to the 20th century. (For years from 2000 all four digits have to be entered, and the calculator is then year
2000 compliant, as demonstrated below).

Enter 12 for the month, press "DATE", press 25 for the day, display shows 1978.12.25, as above.

Press "DATE", display shows 78.12.25 - 1, as above, where the "- 1" indicates Monday (as shown on the chart under the display).

To find the date and the day of the week 16 days later enter "+" and "16", and the display show 79.01.10 - 3, as above, indicating that it will be 10th January 1979 and it will be a Wednesday.

**Demonstration that the Casio AL-8S is 'Year 2000 Compliant'**

Rob Tambini has kindly pointed out that the Casio *AL-8S* is actually 'Year 2000 Compliant', so that it deals correctly with years from 2000 onwards. Here he has entered all 4 digits of the year 2023, instead of just the last two digits for a year which causes the calculator to default to the 20th century and automatically display "19" in front. The display above indicates 6th September 2023.

Pressing "DATE" shows that this is day 3 which indicates Wednesday, as shown on the chart under the display, which is the correct day for that date. Also the addition and subtraction functions appear to work correctly for such dates.

**Hand-held Calculators**

*Vintage Calculators *

Text & photographs copyright, except where stated otherwise, © Nigel Tout 2000-2024.