Bits and Bytes
What do computers know? • All they really know is on or off. • Kind of like a light switch • Computers aren’t nearly as smart as you are!
Integrated Circuits • Contains transistors and capacitors that control the flow of electricity and store electricity. • Can only tell off and on which computer translates into ones and zeros.
What is this language called? • Binary Code or Machine Language • A lot can be accomplished with ones (on) and zeros (off).
Numbering Systems • Decimal – uses the digits 0,1,2,3,4,5,6,7,8,9 • Binary – uses only the digits 0 & 1 • Decimal represents the number forty-three like this 43 • Binary represents the number forty-three like this 00101011
How can computers do all they can do? • A bit (short for binary digit) is the smallest piece of data that a computer knows. • It is a single digit , which can only be a one or a zero. • By combining groups of bits and manipulating them, a computer can accomplish all the remarkable things it has a reputation for doing.
Computers process and store all data, pictures, movies, and sounds as long streams of bits!
How do we communicate with computers then? • We need some way for the computer to translate our language into theirs! • How many different letters, numbers, and symbols do we use to communicate? • If we used just one bit we could only store two possible letters, numbers, or symbols. This doesn’t work!
What is a byte? • A group of 8 bits! • If you wrote down all the possible combinations of ones and zeros that could make up a byte you would have 256! • 00000000 through 11111111 • Or 2 to the eighth power – 28 • 28 equals 2x2x2x2x2x2x2x2
ASCII Code • A set of standards developed so all computers would store letters, numbers, and symbols using the same binary code. • The ASCII Code is an 8-bit or 1 byte code. • Each letter, number, or symbols is stored using one byte of computer memory. • The ASCII Code for C would be 01000011. • The ASCII Code for c would be 01100011.
So how many bytes does it take to store this sentence? • If you said 54 you are correct!
Translate this message! 01001000 01100101 01101100 01101100 01101111
So what is a KB, MB, and GB? • As computers became more and more powerful new terms were needed to describe the amount of bytes. • Compare this to inches versus miles!
What is a kilobyte or KB? • Technically it is exactly 1024 bytes or 210. • Approximately 1000 bytes. • This is equivalent to about ½ of a typewritten page of text.
What is a Megabyte or MB? • Exactly 1,048,576 bytes or 220 • Approximately 1 million bytes • This is equivalent to 500 pages of typewritten text or 1 thick book.
What is a Gigabyte or GB? • Exactly 1,073,741,824 bytes or 230 • Approximately 1 billion bytes • This is equivalent to 500,000 pages of typewritten text or 1,000 thick books.
What is a Terabyte or TB? • Exactly 1,099,511,627,776 bytes or 240 • Approximately 1 trillion bytes • This is equivalent to 1,000,000 thick books.
