Digital Information The Language of Machines

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Digital InformationThe Language of Machines
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Think back to Programming I..

• How is all data stored in a computer?
• Numerically!

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• Computers contain millions of transistorsmicrosco
  pic electronic switches that turn on and off
  millions of times a second to create the computer
  experience you're having right now.
• To process the words, images and sounds we use
  every day, computers and other devices (such as
  CD players) transform these communications into a
  simple code that uses the numerals 0 and 1 to
  represent the on and off states of a transistor.
• This language of 0s and 1s is known as digital
  information.
• As simple as this language may seem, it is
  extremely versatile and has played a major role
  in the greatest technological revolution the
  world has ever seen.

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What types of codes do you use when you dont
want people to understand you?
Video Language
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What is Binary Code?

• People use all kinds of symbols, sounds, colors
  and body motions to express themselves. These
  expressions are, in a sense, codessignals we use
  to communicate with one another.
• Computers use a special code of their own to
  express the digital information they process.
  It's called the binary code because it consists
  of only two symbols0s and 1s. (The "bi" in
  "binary" means two.)
• Why 0s and 1s? Because those are the only two
  numbers you need to express the flow of
  electricity through a transistor. It's either on
  or it's off. On is 1, off is 0. Everything you
  say to a computer has to be put in terms of these
  two numbers.

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Video Binary
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The Binary Number System

• For a computer to execute or respond to a
  command, it has to be translated into the only
  language a computer knows the 0s and 1s of the
  binary number system. The 0s and 1s represent the
  on and off of the transistors.
• What do you call one of these 0s or 1s? A bit.
  Which makes sense when you see how many of these
  bits it takes to represent a word, number, color,
  graphic or sound. They really are just a "bit" of
  something bigger.

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Binary Counting
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Counting in Binary Numbers

• The binary system that computers use to store and
  process information is a base 2 system. It needs
  only two symbols, 0 and 1. In fact, "binary"
  comes from the Latin word for two. Compare this
  to the decimal system you use. The decimal system
  is a base 10 system. ("Decimal" comes from the
  Latin word for ten.) It has 10 symbols (0, 1, 2,
  3, 4, 5, 6, 7, 8, 9).
• So how do you count in a binary system? How do
  you represent numbers like 103?

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• In decimal (base 10) numbers, you have a 1s
  place, a 10s place, a 100s place, and so on, to
  represent value.
• The binary system has places or columns too. Only
  because you're in base 2, instead of each place
  being 10 times greater than the place before it,
  each place is only double (2 times) the one
  before it.

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Decimal Binary Numbers Activities

• Handout Understanding Binary Code
• Converting Decimal and Binary Numbers
• Lets practice some more!
• Making a Decimal-to-Binary Number Conversion
  Chart

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• Since computers cannot think like we do, they
• need a code to translate our language into
• data that they can process and then convert
• that data back into a recognizable language.
• This is why an Alphabet for computers was
  developed in the 1968 called

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ASCIIAmerican Standard Code for Information
Interchange
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ASCII An Alphabet for Computers

• Bits, the 0s and 1s of binary code, can be used
  in many different ways to represent information.
  To make it easier for computers to communicate
  with each other, a standard language has been
  created ASCII (American Standard Code for
  Information Interchange).
• ASCII is an 8-bit code. It uses eight bits to
  represent a letter, number, or punctuation mark.
  For instance, a lower case "a" is represented by
  0110 00012. The word "cat" would be

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Why do you think there is an ASCII code for a
blank space?

• Because we use spaces all the time in our writing
  to separate words and sentences. Every time you
  press the space bar on your keyboard, the ASCII
  code for a blank space is inserted in your
  document. In fact, youll notice the ASCII
  doesnt include characters for the first 31
  binary numbers. Thats because these are used for
  non-printing actions such as enter, tab, and
  delete.

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ASCII Activities

• Write your name in binary code and in ASCII
• Print the binary message decode it
• Need to print this chart
• http//www97.intel.com/discover/JourneyInside/TJI_
  DigitalInfo_lesson6_3/default.aspx

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Unicode

• A 16-bit code that was developed in the 1990s
  that will handle alphabets of many nations.
• Note! The ASCII code is limited to the English
  alphabet.

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Using the Asc function

• Dim strCharacter As String
• strCharacter A
• lblASCII.Caption Asc (strCharacter)
• Asc funtion a VB built-in function that returns
• the ASCII code corresponding to a character.

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Using the Chr function

• Dim intExample as Integer
• intExample 75
• lblASCII.Caption Chr (intExample)
• Chr funtion a VB built-in function that returns
• the character corresponding to an ASCII code.

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How Computers Work With Pictures

• Now picture this. Your computer screen has
  hundreds of thousands of dots arranged in rows
  and columns. Each dot is a picture element or
  pixel. Each of these pixels displays some
  combination of red/green/blue according a device
  called a Video Graphic Array (VGA) The VGA
  translates binary-coded information (0s and 1s)
  into the color combinations required to make up
  an image on your computer screen.
• Video Digital Images

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Digital Images Activities

• Work and play with Pictures
• http//www97.intel.com/discover/JourneyInside/TJI_
  DigitalInfo_lesson3_1/default.aspx
• Make your own pixel pictures
• http//www97.intel.com/discover/JourneyInside/TJI_
  DigitalInfo_lesson3_2/default.aspx