Chapter 1.0 The Information Age & Digital Computers

Programming Concepts Part 1 : Computers –1.0. Information age and Digital Computers –1.1. Digital Computers : Hardware organization –1.2. Digital Computers : Operating Systems –1.3. Computer Networks –1.4. Programming Languages and Programming –1.5. History of Computing Devices

Summary The Information Age Underlying paradigms »3000 bc : Geometry » : Energy » now : Information Digital Computers : Programmable devices to process information – Digital : information encoded by digits – Programmable : »Universal hardware »Specific capabilities defined by Software

Summary The Information Age Underlying paradigms »3000 bc : Geometry » : Energy » now : Information Digital Computers : Programmable devices to process information – Digital : information encoded by digits – Programmable : »Universal hardware »Specific capabilities defined by Software

Geometry Initiated 3000 bc in Egypt for practical purposes Evolved into science in Middle East and Greece Considerable influence on art and architecture Many attempts to model universe by purely geometric constructs

Geometry and Arab Art

Geometry and Civil Engineering

Geometry Initiated 3000 bc in Egypt for practical purposes Evolved into science in Middle East and Greece Considerable influence on art and architecture Many attempts to model universe by purely geometric constructs

Summary The Information Age Underlying paradigms »3000 bc : Geometry » : Energy » now : Information Digital Computers : Programmable devices to process information – Digital : information encoded by digits – Programmable : »Universal hardware »Specific capabilities defined by Software

Energy Laws of mechanics, with notions of Force and Energy discovered by Galileo, Newton et al.... Results in replacement of muscular force by machines : The industrial revolution. Industrial revolution results in social turmoil: –French revolution (1789) –US civil war (1865) Considerable influence on sciences –Conservation laws (Mass, Energy, Movement,....) –Understanding of electrical phenomena

Energy : the first industrial revolution

Energy Laws of mechanics, with notions of Force and Energy discovered by Galileo, Newton et al.... Results in replacement of muscular force by machines : The industrial revolution. Industrial revolution results in social turmoil: –French revolution (1789) –US civil war (1865) Considerable influence on sciences –Conservation laws (Mass, Energy, Movement,....) –Understanding of electrical phenomena

Summary The Information Age Underlying paradigms »3000 bc : Geometry » : Energy » now : Information Digital Computers : Programmable devices to process information – Digital : information encoded by digits – Programmable : »Universal hardware »Specific capabilities defined by Software

Information From 1837 on, energy is used to carry something even more precious: information – 1837 : Electric telegraph (Samuel Morse) – 1876 : Telephone Information acquires essential role in science : –Uncertainty principle introduced by Heisenberg and Quantum Mechanics –Discovery of role of DNA in Biology Information technology > Industrial Revolution – Repetitive intellectual tasks done by machines – Spectacular increases in productivity

Information : Human voice carried by electricity

Information From 1837 on, energy is used to carry something even more precious: information – 1837 : Electric telegraph (Samuel Morse) – 1876 : Telephone Information acquires essential role in science : –Uncertainty principle introduced by Heisenberg and Quantum Mechanics –Discovery of role of DNA in Biology Information technology > Industrial Revolution – Repetitive intellectual tasks done by machines – Spectacular increases in productivity

Information : DNA : the key to modern biology

Information From 1837 on, energy is used to carry something even more precious: information – 1837 : Electric telegraph (Samuel Morse) – 1876 : Telephone Information acquires essential role in science : –Uncertainty principle introduced by Heisenberg and Quantum Mechanics –Discovery of role of DNA in Biology Information technology > Industrial Revolution – Repetitive intellectual tasks done by machines – Spectacular increases in productivity

Summary The Information Age Underlying paradigms »3000 bc : Geometry » : Energy » now : Information Digital Computers : Programmable devices to process information – Digital : information encoded by digits – Programmable : »Universal hardware »Specific capabilities defined by Software

Summary The Information Age Underlying paradigms »3000 bc : Geometry » : Energy » now : Information Digital Computers : Programmable devices to process information – Digital : information encoded by digits – Programmable : »Universal hardware »Specific capabilities defined by Software

Digital Techniques (Information encoded as digits) 6:12:08 Analog Digital

Digital Techniques Representation of numbers in electronic devices ? Binary numbers (base 2) are used. A binary digit (bit) can be represented by a switch: –Value 0 : switch open –Value 1 : switch closed A number with n bits can take 2 n different values –2 bits : 4 combinations –3 bits : 8 combinations –8 bits (= 1 byte) 256 combinations –16 bits: combinations –24 bits: combinations –32 bits: combinations

Digital Data Representations Information is encoded by numbers Sound: samples per second for CD’s Images: –Bit maps: regular raster of points. –Geometric patterns. Texts: each character encoded by a number Numbers: integers and floating point numbers

Music Records Analog Digital

Music Records Analog Digital (CD) (44100 measurements/s)

Records with a scratch Analog Digital (CD) XXXX

Digital Data Representations Information is encoded by numbers Sound: samples per second for CD’s Images: –Bit maps: regular raster of points. –Geometric patterns. Texts: each character encoded by a number Numbers: integers and floating point numbers

Graphical encoding Bit Maps (.bmp files in DOS) –Luminosity and color of each point of a regular raster is encoded –Very versatile but requires a lot of memory. Geometric coding : –Straight lines between two points –circle with given center, radius, color and intensity –Very efficient for computer generated images Geometric coding > bit maps : OK Bit maps > Geometric coding : Very Difficult: jpeg, mpeg,...

A bit map Size = 10 MBytes

An other bit map Size = 10 MBytes

Graphical encoding Bit Maps (.bmp files in DOS) –Luminosity and color of each point of a regular raster is encoded –Very versatile but requires a lot of memory. Geometric coding : –Straight lines between two points –circle with given center, radius, color and intensity –Very efficient for computer generated images Geometric coding > bit maps : OK Bit maps > Geometric coding : Very Difficult, jpeg, mpeg,...

A geometric construct Size = 13 KBytes

Graphical encoding Bit Maps (.bmp files in DOS) –Luminosity and color of each point of a regular raster is encoded –Very versatile but requires a lot of memory. Geometric coding : –Straight lines between two points –circle with given center, radius, color and intensity –Very efficient for computer generated images Geometric coding > bit maps : OK Bit maps > Geometric coding : Very Difficult : jpeg, mpeg,

Digital Data Representations Information is encoded by numbers Sound: samples per second for CD’s Images: –Bit maps: regular raster of points. –Geometric patterns. Texts: each character encoded by a number Numbers: integers and floating point numbers

Extended ASCII Character Set (8 bit)

Texts on PC's This is a text demo Aaé

Digital Data Representations Information is encoded by numbers Sound: samples per second for CD’s Images: –Bit maps: regular raster of points. –Geometric patterns. Texts: each character encoded by a number Numbers: integers and floating point numbers

Numbers ASCII Characters :8 bit / digit. BCD Characters : 4 bit / digit. Binary numbers : 2 n values Example: In a 32 bit word: Binary : BCD : ASCII : 0 <= x <=

Floating Point Numbers R = (-1) S. M.base E 3 parts: Sign, Mantissa, Exponent base = predefined constant (2 or 16) majority of computer systems : IEEE754. Single precision (32 bit) “float” Smallest value: Largest value : Relative error: <

Summary The Information Age Underlying paradigms »3000 bc : Geometry » : Energy » now : Information Digital Computers : Programmable devices to process information – Digital : information encoded by digits – Programmable : »Universal hardware »Specific capabilities defined by Software