Visual Basic

ASCII to Chip

Remember this guy? How did he get to be a powerful robot? What was his mission?

Or, let's ask a simpler question: How does your computer display a letter "A" on the screen when you press the "A" key on your keyboard?

On your keyboard, press the "A" key. Then the keyboard sends the data to the CPU which instructs the monitor to display the letter "A". But how does the information pass through different parts of the computer? For example, each key on the keyboard is essentially a switch that is either on when it is pressed, or off when it is not pressed. Then the on/off information of the key is sent to the computer (CPU) to determine if the key pressed is the "A" key. Based on that information, it computes and sends instruction (data) to the monitor to display the letter "A" on the screen by manipulating pixels to form the letter "A".

In ASCII, the letter "A" is 41 in hex (65 in decimal ), and 0100 0001 in binary.

The following table shows the flow of converting "A" to a mechanical machine level takes place.

Your keyboard
"A"
In Hex.
41
Separate to 2 digits
4
1
 
Find decimal equivalent for conversion purpose
8
4
2
1
8
4
2
1
Actual equivalent of decimal (64 + 1 = 65) 128 64 32 16
8
4
2
1
 
In Binary
0
1
0
0
0
0
0
1
The computer chip processes the binary number, and instructs the screen to turn on certain pixels to display the letter "A".
* Each digit of binary number is called a bit while a set of 8 bits is called a byte. (The convertor)

 

With 0100 0001 in binary number, you can simulate a simple circuitry on the chip below.

Let's say each pin of the chip represent each digit of a 8-digit binary number.

By instructing certain pins to have electricity to go through (switch on), you can perform particular tasks, such as displaying the letter "A". Let's say, using the information from the binary number 0100 0001, turn Pin 1 and Pin 7 to be "on". The circuits in the chip can compute to instruct the letter "A" to be displayed.