Overview of computers and programming

Overview of computers and programming

• 1.
  Introduction to ComputerProgramming Introduction Overview of Computers and Programming Languages C++ Programming: From Problem Analysis to Program Design
• 2.
  Overview of Computersand Programming Languages
• 3.
  Chapter Contents • ComputerHistory • Elements of a Computer System – Hardware – Software • Language of a Computer • Evolution of Programming Languages • High Level Languages • Analysis‐Coding‐Execution • Object Oriented Programming
• 4.
  Computer History • 1950's –Large devices, accessible to few people • 1960's – Commercial usage emerges – Operated by experts • 1970's – Computers cheaper, smaller • 1990's – Computers fast, small, inexpensive – Owned and used by many people
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  Elements of aComputer System Hardware CPU The "brain" of the computer Main Memory Data and instructions stored to, fetched from • Keyboard • Disk drive • Scanner • Mouse • Screen • Printer • Plotter • Hard drive • Zip‐Disk • CD‐Rom • Tape Backup
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  Elements of aComputer System Software • Systems programs – Control the computer – Includes Operating System (ex: windows, Apple Mac, Chrome OS etc..) • Applications programs – Word processors (wordpad, MS Word) – Compilers (MSVS, C++ Builder) – Spreadsheets (MS Excel) – Data Bases (MS Access)
• 7.
  The Language ofa Computer • Uses digital signals – all 0's and 1's (binary) – bits (BInary digiTs) • Data and commands stored in binary – 8 bits in a byte – ASCII character stored in a byte – Integers stored in 2 or 4 bytes
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  ASCII Code American StandardCode for Information Interchange
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  Evolution of ProgrammingLanguages • Early computers programmed in machine languages – All binary numbers • Assembly language used mnemonic codes – Codes translated into machine language by a program called the "assembler"
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  Evolution of ProgrammingLanguages • High level languages read like combination of English and algebra – Translated into machine language by a program called a compiler
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  Analysis‐Coding‐Execution Problem solving process 1.Analyze problem, design solution algorithm 2. Implement algorithm in a programming language, verify 3. Maintain program, adapting it to changes in problem requirements
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  Analysis‐Coding‐Execution • Algorithm :A step‐by‐step problem‐solving process in which a solution is arrived at in a finite amount of time – Steps must be simple, unambiguous – Steps must be performed in specified order – Steps must solve the problem
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  Analysis‐Coding‐Execution Analysis and algorithm design doneapart from any specific programming language Processing of the high‐level language programming language
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  Processing a High‐LevelLanguage Program 1. Source program created with an editor 2. Source code translated into machine language by compiler ‐ Results in a “.obj” file (object code) 3. Linker combines common library routines with object code ‐ Results in a “.exe” file (executable code) 4. Loader brings executable code into memory and it is run
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  Processing a High‐LevelLanguage Program
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  Structured Programming • Thoroughlyunderstand the problem • Determine – the output desired – the required input – processing that will occur • Divide the problem into sub‐problems