It’s A Binary World - How Computers Count.
Many have cursed their computer for taking things too literally It’s easy to blame the computer when something goes wrong.
You get to the checkout at the market & the item you bought ‘on special’ comes up at the full price. The manager has to be called to fix it up & what does he say?
“We’ve been having problems with the computer it gets the wrong price on some things.”
You put in a list of addressess to your Word processor & print off party invitations for next week. Then you find that today’s date has been inserted in the signature block by the computer
Maybe you have heard the expression ‘Garbage in Garbage out”? Someone at some point instructed the computer to do what it did It didn’t decide to screw you up deliberately. Computers can only do what they are told they are more logical than Spock & they take everything literally.
We are going to look at why they are so pedantic
The world around us has many aspects which work in the same way as a computer. There are many examples of opposites for instance Up & Down Left & Right Forwards & Backwards. A light may be On or Off maybe it’s Night or Day. Yes or No? You can think of many others. This system of two possible states is called a Binary System if it’s not one it must be the other.
A computer uses the Binary System to perform all its functions the basic unit originally a vacuum tube then a transistor then a chip is used thousands of times over to make the total unit. The light being On or Off which we mentioned above is controlled by a switch. In the computer this switch is transistor which is either On or Off.
Now we get to the Math Don’t worry it’s very simple Math In fact it’s so simple we only count up to 1. That’s right we can only have two states so we count from 0 to 1. That’s another thing computers are pedantic about they insist on starting at zero .
The Binary system is Number System. You are familiar with the Decimal system which has 10 numerals 0 to 9 think like a computer 0 comes first . You can make up all sorts of number systems for whatever purpose you want. You probably know about a dozen 12 & have also heard of a half dozen. If you’ve used your computer much you may have come across the Hexadecimal system. This one has 16 ‘numerals’ 0-9and A-F. Another number system used by computer people is the Octal system which has 8 numerals 0-7.
Ok so how do we count with only 0 & 1. Simple in exactly the same way you count in decimal. The first ten numbers are OK 0-9 but what next? We start again but add in a 1 making 10 or “one zero”. This gets us to “one nine” & we go to “two zero” & so on up to “nine nine” then we again add a 1 to make 100 “one zero zero.”
If you’ve followed me so far you are ready for the Binary sequence it’s much simpler. Starting off at zero we have 0,1 & that’s it. We follow the same rule & add in a 1 making “one,zero”. Next come “one one”; then “one zero zero”; -”one zero one”; etc. These are equivalent to Decimal 0,1,2,3,4,5. How does this relate to computers? That’s next.
In our computer we have transistor switches as described above. For the math example we just looked at we need 3 switches. These each represent a Binary Digit or Bit. To represent a Decimal 1 these switches would be OFF,OFF,ON or 001. For a Decimal 5 we would have ON,OFF,ON or 101. By extension you can see that with 4 switches we could go to 1111 or 15 Decimal.
Another point to note is that each binary digit or bit has a value. Just as in Decimal we have units tens hundreds etc. in Binary the values are 1,2,4,8,16,32,64,128 etc. etc. The binary code 1111 mentioned above is thus 1+2+4+8=15. If you wanted to work out what binary 100101100 was in decimal you could add up the individual values. In fact people who work on the basic machines need to know “machine code” To them 1111 would be F in Hexadecimal or 17 in octal.
This probably seems a very long-winded way to work out numbers until you remember that these ’switches’ can operate at nanosecond speed or 1,000,000,000 times per second large calculations become possible.
Thats probably enough to digest in one go. Next time we will look at how a computer adds & multiplies.
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Fat Loss 4 Idiots
Fat Loss 4 Idiots
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