Von Neumann architecture basis for today's computers. ◇ VLSI Technology
made computers affordable, small and available to the public. ◇ How
programming ...
Introduction to Computers, Problem Solving, and Programming Chapter 1
1.1 Overview of Computers t
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Computer - “A device for counting or computing” Dr. John Atanasoff - 1st computer. ENIAC 1946 at U of Penn Dr. John Von Neumann - Princeton – Stored program concept – Memory rather than wires and switches.
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Computing History 2
Overview of Computers t
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Von Neumann architecture basis for today's computers VLSI Technology made computers affordable, small and available to the public How programming has changed over time
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1.2 Computer Hardware t
Every computer is organized roughly into six parts – CPU - central processing unit • Where decisions are made, computations are performed, and input/output requests are delegated
– Main Memory • Stores information being processed by the CPU
– Secondary Memory • Stores data and programs 4
Computer Hardware – Input devices • Allows people to supply information to computers
– Output devices • Allows people to receive information from computers
Semi permanent data-storage capability – Tape or Disk – Hard disk – CD ROM
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Secondary memory has much more storage capacity 9
CPU t
“Brains” of the computer – Arithmetic calculations are performed using the Arithmetic/Logical Unit or ALU – Control unit decodes and executes instructions
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Arithmetic operations are performed using binary number system
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CPU t
Fundamental building block is a switch – Switches are made from ultrasmall transistors
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Examples – The Pentium ® processor contains about three million transistors – The Pentium Pro ® has about 5.5 million transistors
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Input / Output Devices t
Accessories that allow computer to perform specific tasks – Receiving information for processing – Return the results of processing – Store information
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Common input and output devices – Printer – Keyboard
Joystick Monitor
CD-ROM
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Computer Networks t
LAN - Local area network – Organizational
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WAN - Wide area network – Internet
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World Wide Web t t
Introduced 1989 Developed by CERN – European Laboratory for Particle Physics
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Web browser – GUI – Netscape – IE 14
1.3 Computer Software t
Application software – Programs designed to perform specific tasks that are transparent to the user
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System software – Programs that support the execution and development of other programs – Two major types • Operating systems • Translation systems
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Application Software t
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Application software is the software that has made using computers indispensable and popular Common application software – – – – –
Controls and manages the computing resources Important services that an operating system provides – File system – Commands that allow for manipulation of the file system – Ability to perform input and output on a variety of devices – Management of the running systems Examples – MSDOS ®, Windows ®, Unix ® 17
Programming Languages t
Machine Language – “Native tongue” of the computer – Binary 0s and 1s that specify what to do • 0010 0000 0000 0100 • 1000 0000 0000 0101 • 0011 0000 0000 0110
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High - Level Languages – Resemble human language (C++, C, Pascal) • cost = price + tax; 18
Programming Languages t
Language Standard – Syntax (grammatical form) (rules) – Portable • programs used without modification
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Source Program Object Program Executable Program 19
1.4 Processing a High-Level Language Program t t t
Set of programs used to develop software A key component of a is a translator Types of translators – Compiler – Linker
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Examples – g++, Borland C++ ®, Microsoft Visual C++ ® 20
Processing a Program t
Editor used to enter the program – Source program (file.cpp) – UNIX vi text editor
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Compiler translates the source program – Displays syntax errors (not descriptive)
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Linker/Loader to combine object file with other object files – Executable program 21
Processing a Program t
Major activities – Editing – Compiling – Linking with pre-compiled files • Object files • Library modules
– Loading and executing – Viewing the behavior of the program 22
