Operating Environments

1
Operating Environments

• Introduction

2
Computer Overview
Output
Input
Raw Data
Information
Processing (Transformation of raw data into
meaningful information)
3
Computer Hardware

• Primary Components

CPU
Central Processing Unit
RAM
Random Access Memory Main Memory Memory
Primary Storage
4
Contents of Memory
CPU
O.S. Apps Data
Operating System Application software Documents
5
Peripherals
Monitor
Keyboard
CPU
Printer
Mouse
Memory
Modem
Hard Disk
Floppy
Scanner
6
Peripherals

• What are some other peripheral devices?
• Are they input or output devices?

7
Auxiliary Storage
Tape
Hard Disk
CPU
Memory
Floppy Disk
CD
8
Auxiliary Storage

• Mass storage
• Secondary storage
• Special kind of peripheral device
• Permanent storage of programs and data
• Contrasts with primary storage (memory)

9
Storage Characteristics

• Main Memory Auxiliary Storage
• Temporary - Permanent
• (volatile)
  (non-volatile)
• Small quantity - Large quantity
• Fast - Slow
• High cost - Low cost

10
Computer Software

• Instructions for the CPU
• Allows transformation (processing) of data into
  information
• Terminology
• Programs
• Applications
• Software

11
Types of Software

• System software deals with the computer system
• Operating system
• System utilities antivirus, backup,
  defragmentation
• Development tools editors, compilers,
  interpreters
• Application software deals with users
  activities
• End-user programs
• Word processing
• Spreadsheet
• E-mail
• Etc.

12
Operating System

• Most important piece of system software
• Master control program
• Manages the computer resources
• Manages computer hardware
• Manages programs

13
Location of O.S.

• O.S. transferred to memory (loaded)
• at boot time from auxiliary storage

CPU
Load
O.S.
O.S.
Memory
Hard Disk
14
O.S. Components

• Processor manager
• Memory manager
• Device manager
• File manager
• User command interface
• Components communicate and cooperate to perform
• the fundamental operations of the computer

15
Processor Manager

• Manages the CPU
• Controls execution of instructions
• Controls transfer of instructions and data
  between memory and CPU
• Manages program priorities
• Manages program interruptions
• Manages multitasking

16
Memory Manager

• Manages main memory
• Keeps track of occupied and free space
• Retrieves and stores instructions and data

17
Device Manager

• Manages peripheral devices
• Understands languages of devices
• Transfers data between hardware
• Handshaking

18
File Manager

• Manages files stored on auxiliary storage media
• Files programs and documents
• Tracks location of files
• Defines storage formats

19
User Command Interface

• Processes commands entered by user
• Command interpreter
• Types
• Graphical user interface (GUI)
• Command line

20
Network/Security Management

• Manages logon authentication
• Manages network resource access
• Monitors for security issues

21
GUI Characteristics

• Icons
• Menus
• Mouse driven
• Windows
• Ease of use intuitive
• Examples
• MS Windows (3.x, 9x, Me, NT, 2000, XP)
• Mac OS
• Unix X Window System

22
Command Line Characteristics

• Commands entered on a line
• Parameters and switches
• Memorization of commands
• Less easy to use less intuitive
• Examples
• DOS
• Unix shell
• VMS (VAX mini computer)

23
Relationships
User
User command interface
Application
O.S. acts as interface to hardware
Operating System
Hardware
Majority of CIS 140 deals with the user command
interface