Computers? Those are ancient!

The first computer was invented in the 20th century right?...WRONG! Computers have been around for much longer than you'd guess, I realized that in today's class. To understand this better I first have to define a computer. A computer is any device that can take in information, process this information and give you back information in return. So basically, a lot of things can be a computer, but the term is more widely used for the digital computers we use today. We were given an example of an early computer; an abacus. Another example of a computer is the flight computer, which consists of wheels and sliders that help you come across an answer to a mathematical problem you arrange on the device.

The digital computers we use today consist of output and input devices. Input devices help us put information into the computer, and output devices that give us feedback/results from the data we put in.

Examples of Input Devices:
- Mouse
- Keyboard
- Graphic Tablet
- Camera

Examples of Output Devices:
- Monitor
- Printer
- Speakers

With the help of these devices you can send the computer data and receive some sort of feedback in the form of more information. But the computer can only understand and process to things, these are the numbers 0 and 1. How does it perform all those functions then?!

Binary Digit System and Base 10 System

The computer is based on a binary digit system, or a base 2 system. This means that there are only two digits in the system: 0 and 1. With 0 and 1, you can turn things on and off. Those, however, are still only 2 functions.

In everyday lives we use the base 10 system, which has 10 digits. These 10 digits were first chosen because we have 8 fingers and 2 thumbs on our hands, that makes up 10. The digits this system consists of are, you guessed it, 1, 2, 3, 4, 5, 6, 7, 8, 9 and 0.

Both these systems are based on the same principle, and that is a place value system. In the base 10 system we have 10 digits, which is the reason why the place values grow by multiplying by 10.

This example shows the base 10 system and how it represents numbers. The number 20 is used as an example, to form 20 you would need 2 10's, which is why 2 is in the 10's place value column. There are 0 1's needed for this, thus the place value below 10 (1) has a 0 in it's column.



The Binary Digit System works in the same way, but the place values grow by multiplying by 2 since there are two digits. So there is an endless amount of possibilities of numbers that the computer can create to represent different things. Every action you take sends a stream of 0's and 1's to the processor and the information is returned to you as what the 0's and 1's represent. So when you press the "A" key or any other key, the computer is not recieving the letter "A", the computer recieves a number value that represents that key.

The example below shows how the number 20 would be represented by the binary digit system. Since the highest place value you can go to b efore going above 20 is 16 a 1 is placed there. Now we have 16 we need 4 more to make up 20. 8 is too much so a 0 is placed there. 4 is what we need so there's a 1 and the 2 before it is also not needed so a 0 is placed there as well



This is basically how the binary digit system works. The computer functions on this system.