Wk 1 computer

• Computer system software

  Sets of instructions written to drive/run the hardware
• Types of Software

  • System Software
  • Application Software
• Types of Software

  • System Software: Operating System (OS)
  • Application Software: Various specific examples
• System Software

  Contributes to the control and performance of the computer system
• System Software


  Designed to run a computer’s hardware and application programs
• System Software


  Collection of suites of programs written by the computer manufacturer to control and enhance the performance of the computer
• Types of System Software

  • Operating System (OS)
  • Computer Language Translator
  • Utilities Programs
• Operating System (OS)


  Set of instructions designed to efficiently manage the resources of the computer system
• Operating System (OS) performs services for applications


  Determines which applications should run in what order, manages sharing of internal memory, handles input and output to and from attached hardware devices
• Operating system

  1. Determines which applications should run in what order and how much time should be allowed for each application before giving another application a turn

  2. Manages the sharing of internal memory among multiple applications

  3. Handles input and output to and from attached hardware devices, such as hard disks, printers, and dial-up ports

  4. Manages how to divide the program so that it runs on more than one processor at a time

  5. Sends messages to each application or interactive user (or to a system operator) about the status of operation and any errors that may have occurred
• Types of Operating System

  • Single user Operating System
  • Multiple user Operating System
• Single user Operating System


  Makes the computer system available to only one user at a time
• Single user Operating System

  • DOS (Disk Operating System), Macintosh Operating System, Apple DOS, Windows Operating System
• Multiple user Operating System

  Designed to be shared by many users
• Computer Language Translator
• A programming language is a set of notations in which computer programs are expressed
• The only language a computer understands is machine language using the binary system (0’s and 1’s)
• Translators

  • Assembler
  • Interpreter
  • Compiler
• Utility Software

  System software designed to help analyze, configure, optimize, or maintain the operation of a computer, its devices, or its software
• Utility Software

  • Disk utilities like defragmenters, compressors, cleaner, antivirus programs, registry cleaners, Screen saver, file viewer (windows explorer), editors, system restoration programs
• Utility software is built into the computer operating system, however, may be installed separately
• Translator


  Highly developed programs capable of converting high-level language to machine language, low-level language to machine language
• Translator


  Computer program that performs the translation of a program written in a given programming language into a functionally equivalent program in a different computer language without losing the functional or logical structure of the original code
• Types of Translator


  • Assembler
  • Compiler
  • Interpreter
• Assembler


  Translates assembly language into machine code
• Assembler


  Used to translate the program written in assembly language into machine level language
• Example for Assembler Translator

  • FAP
  • Fortran Assembly Program
  • MAP
  • Macro Assembly Program
• Advantages of using Assembler

  • Very fast in translating assembly language to machine code as 1 to 1 relationship
  • Assembly code is often very efficient because it is a low-level language
  • Assembly code is fairly easy to understand due to the use of English-like mnemonics
• Disadvantages of using Assembler

  • Assembly language is written for a certain instruction set and/or processor
  • Assembly tends to be optimized for the hardware it’s designed for, meaning it is often incompatible with different hardware
  • Lots of assembly code is needed to do relatively simple tasks, and complex programs require lots of programming time
• Compiler


  Capable of converting high-level language to machine language directly
• Compiler


  Computer program that translates code written in a high-level language to a lower-level language, object/machine code
• Compiler


  Reads the complete source program written in high-level language, converts it into machine level language if error-free
• Compiler


  Specifies errors at the end of compilation if there are any errors in the source code
• Example for Compiler Translator

  • GCC
  • GNU compiler Collection
  • COBOL
  • Common Business Oriented Language
• Advantages of Using a compiler

  • Efficiency: Compiled code tends to be more efficient in terms of execution speed compared to interpreted code
  • Performance Optimization: Compilers can perform various optimizations during the compilation process
  • Portability: Compiled code is often more portable than source code
• Compiler


  • Dead code elimination can lead to improved performance
• Compiler


  • Portability: Compiled code is often more portable than source code
• Compiler


  • Code Protection: Compiled code can be more challenging to reverse engineer compared to interpreted code
• Compiler


  • Error Checking: Compilers perform extensive static analysis on the source code, catching many types of errors before the program is executed
• Disadvantages of Using a compiler