Computer Devices (Mr. R.Caruana)

Pascal Calculator.

This device was considered as the first type of mechanical calculator. It was developed by Blaise Pascal in 1642.

Because of its parts used for this machines its cost was too expensive and therefore it wasn't affordable for most of the people at those times. Also because of this reason, only 50 machines were made and nowadays the ones left (about 8 in total) are being kept in a Museum in Paris.

Pascal Calculator 'Pascaline'

How it used to work?

This devices used to calculate with 8 figures. The main part used in this device to work was the gear. There was a gear for every figure with ten teeth each (one for each number) and when it completes one rotation, the gear next to it will move to one tooth until it makes one rotation (rotate ten times) and the other gear next to it will move, and it keeps on going like that until all figures are used if needed.

For addition:
At the bottom, the turning discs set up the numbers which will be added and the answer will be shown in a window.
For subtraction:
The machine had to be changed to count backwards.
For division and multiplication:
The addition and subtraction had to be done and repeated.

Reference:

http://www.thocp.net/hardware/pascaline.htm