Bits, Bytes and Kilobytes
This lecture on Binary focuses on:
- What a BIT is
- What a BYTE is
- Kilobytes
- Megabytes and Gigabytes
- A Computer WORD
Introduction
Think of a simple light switch. It can be in one of only two states. A switch is either ON or OFF. Not both at the same time. If the switch is OFF we can represent that state as 0. However, if the switch is ON we represent that state as 1 using the binary number system.
What a BIT is
A BIT is a binary digit ( 1 or 0 ) and it is the smallest amount of data a computer can mainpulate or process.
What a BYTE is
A group of eight bits form one BYTE. A computer needs one byte of storage space to store a single character. The word INFORMATION will need to be stored in eleven bytes of storage space because the word INFORMATION is made up of eleven characters.
How much storage space do you think a computer needs to store the phrase "Computers need instructions." ? Do not include the double quotation marks. The answer is given at the bottom of this page. Try to work it out then scroll down for your answer.
Kilobytes
The word Kilo indicates one thousand so a kilobyte is roughly one thousand bytes. It is exactly 1024 bytes thought.
Megabytes and Gigabytes
A PC would have had the storage capacity of a few megabytes two decades ago. If we download a tune from the net to our computer we need approximately five megabytes of storage space to save the average MP3 music file. MP3 is the name used to refer to a popular audio file format.
Mega means million. One megabyte is approximately one million bytes (1,000,000) of data.
One Gigabyte is approximately one billion bytes (1,000,000,000) of data.
One Terabyte is approximately one thousand gigabytes of data. A single TB could hold 1,000 copies of the Encyclopedia Britannica.
Computer Word
A computer word is the number of bits a computer is designed to process in one operation. Many personal computers process 32 bits or 64 bits of data at a time. We can expect that a 64 bit computer would be twice as fast as a 32 bit computer working on the same task.
Answer to the question : The phrase "Computers need instructions." needs twenty-eight bytes of storage space. We must use one byte to store each individual character including the full stop or period at the end of the phrase. Each space in the phrase also requires one byte of storage space. There are 26 individual characters and two spaces in the phrase.
Lecturer:
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The Tutor |
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