Bits and Bytes

So just what is a byte anyway? When folks are speaking computer-eze, you'll hear "byte" or "megabyte" or "gigabyte" every time they open their mouths! It's easy enough to remember that mega means million and giga means billion but a million or a billion what?

Well, to understand "byte" you first need to know what is meant by "bit". We all know that in common usage, a bit is a small piece, a portion of something larger....a bit part in a movie or a bit of inflation. In computer talk, a bit is a single character in a language having only two characters. In other words a bit is either "on" or "off"; "Yes" or "No"; "black" or "white" where there is no gray; "is" or "isn't". If there are only two choices, a bit can be either one of them.

All electronics works on the principle of "on" or "off". Your computer, your TV, your electric razor is on or it is off.

Imagine a world in which you tried to communicate with another person using only "Yes" or "No". You wouldn't even know what you were replying "Yes" or "No" to and that can get you into trouble fast!! So bits may be enough for a hair dryer but they are not enough for human beings.

A byte is 8 bits. It's that simple. If all you have are two options but you can arrange those options into eight places, you then have 256 combinations which can represent words or numbers or symbols. Look at it this way: You have eight switches and each of these swiches can be on or off, beginning with "off, off, off, off, off, off, off, off" and ending with "on, on, on, on, on, on, on, on". You can rearrange the switches into 256 different patterns. Replace the "on" and "off" with "one" and "zero" and you begin to see what a byte looks like.

For example: the letter "A" is represented as "11000001", it is 8-bits long; therefore, it is a byte. The letter "a" is represented as "10000001" . Your computer doesn't know any rules of capitalization; to your computer the letter "A" and the letter "a" are just two different bytes.

The term "byte" is sometimes used interchangeably with the term "character" but they are not identical. A byte representing a number may only be four bits long because there are only 10 numbers.

OK for the English alphabet which only has 26 regular characters and 26 Capitalized characters and 10 numbers (counting 0). One would think that 256 different combinations are plenty for all the symbols and punctuation marks, etc. that English uses. And they are.....but English is not the only language. The Japanese need a system which can represent their 50,000 Kanji characters. So computers have developed 16-bit systems. If you have 16 switches which can each be "on" or "off", you have approximately 64,000 possible combinations.

Now, where will you hear the terms megabyte and gigabyte? And why is it important for you to understand them?

• Memory:

  You may be told that your computer has "32 Megabytes of RAM". That means it can store 32 million characters, short term.

  For example, as I am typing this, all the words and punctuation are going into short term memory or RAM. If I turn my computer off, it's all gone. If I had only 100 bytes of memory, I could only type about 20 words before running up against the limits of my computer. To be able to store 32 million characters means I can type about 6 million words.....not that I am likely to do so without saving my work into long-term memory!

  Additional Information:
       Memory
       Storage

• Software:

  Anytime you acquire software, whether buying it or downloading it from the internet, it will have size information. The program or the box will say something like:
  

  • Minimum System Requirements:
  • IBM compatible PC;
  • Windows 95 or Windows 98;
  • 32M RAM;
  • 50M free hard disk space.

  That means that in order to use this software, your computer must have 32 Megabytes (32 million bytes) of RAM and 50 Megabytes (50 million bytes) of free space on the hard drive available.

  To find out how many bytes (hopefully megabtyes) you have available in RAM and on your hard drive, go to the My Computer icon on your desktop. Under "General System Properties" you will find the number of RAM bytes.

  You can also get this information from Start->Programs->Accessories->System Tools->System Information which will also tell you how much space you have available on all of your drives.

  • Serial vs Parallel Ports:

    How bits are transmitted is a function of ports.

    Ports are a method of getting information into or out of a computer.

    Serial ports have a single input or output line where information is fed in (or fed out) in a stream, one bit following the next. To transmit a byte out a serial port, it goes out 1 bit at a time.

    A mouse is an example of a device that would use a serial port.

    A parallel port, on the other hand, has 8 lines that information is transmitted over 8 bits (or 1 byte) at a time. A printer is the most common parallel port device.

    See Main Boards section on Ports.

  • Color Display:

    The number of colors displayed is a factor of Video Cards - or vice versa; the amount of video memory will determine the number of colors that can be displayed. If each pixel has 4 bits of memory assigned to it, it could be one of 16 possible colors. If it has 8 bits, it could one of 265 possible colors. 16 bits would give you 64 thousand possible colors and 24 bits would give you over 16 million possible colors.

    Additional Information:
         Video Ram

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