Computers The End User s Perspective z Hardware z

Computers: The End User’s Perspective z Hardware z Software z Applications z Operating Systems z Types of Computers Types of Operating Systems y DOS, Windows, … y Unix, Linux y Other Courtesy of: The Computer Continuum

What Is a Computer z Definition: y A computer is a device which takes data in one form, uses it, and produces a different form of information which is related to (but not the same as) the original data. Courtesy of: The Computer Continuum

Basic Concepts of Computers z Minimal configurations of a typical computer include: x x input units output units memory central processing unit Courtesy of: The Computer Continuum

Basic Concepts of Computers z Computer Hardware x The electronics and associated mechanical parts of the computer. z Computer Software x Consists of instructions that control the hardware and cause the desired process to happen Courtesy of: The Computer Continuum

The Many Kinds of Computers z General-purpose Computers x Were not manufactured to do any one thing. x Changeable to do any task. z Special-purpose Computers x Manufactured to do a predetermined task or set of tasks. Courtesy of: The Computer Continuum

The Many Kinds of Computers z Digital Computers x One that functions in discretely varying quantities. x Produces or gives results that are also discretely varying. z Analog Computers x One that functions in continuously varying quantities. x Produces or gives results that are also continuously varying. Courtesy of: The Computer Continuum

The General-Purpose Digital Computer z The General-Purpose Digital Computer x Accepts information of many kinds. x Changes it in a way that is controlled by humans. x Presents results in a way usable by humans. Courtesy of: The Computer Continuum

The Von Neumann Computer and Beyond z Microcomputer Input Units Memory CPU (Central Processing Unit) Input Units: Keyboard Floppy disk Hard disk Mouse CD ROM Output Units: Screen Floppy drive Hard disk Printer Speakers Courtesy of: The Computer Continuum

The Von Neumann Computer and Beyond z Minicomputer Memory Input Units CPU (Central Processing Unit) Input Units: Several Keyboards Floppy disk(s) Hard disk(s) Several Mice CD ROM(s) Output Units: Several Screens Floppy drive(s) Hard disk(s) Printer(s) Speakers(s) Courtesy of: The Computer Continuum

The Von Neumann Computer and Beyond z Mainframe computer Input Units Memory CPU (Central Processing Unit) Input Units: Many Keyboard (Hundreds? ) Massive Hard disk Courtesy of: The Computer Continuum Output Units: Many Screens (Hundreds? ) Massive Hard disk Printer(s)

The Von Neumann Computer and Beyond z Supercomputer Input Units: Many Keyboard (Hundreds? ) Massive Hard disk Memory CPU (Central Processing Unit) CPUs: From many (from 4) To thousands (65, 537) Courtesy of: The Computer Continuum Output Units: Many Screens (Hundreds? ) Massive Hard disk Printer(s)

What Is an Operating System? z The operating system: y A collection of programs that help you use the computer. y Acts as a smart assistant that moves information around the computer. y Allows use of (partial list!) x x x x the keyboard the mouse printing to a printer of your choice viewing information on a monitor saving or retrieving files formatting a disk running programs controlling any external device attached to the computer Courtesy of: The Computer Continuum

What Is an Operating System? z Where does the operating system reside? y ROM (Read Only Memory) x Contains the skeleton operating system. x The skeleton operating system allows use of keyboard and both floppy and hard disk drives. y RAM (Random Access Memory) x The main part of the operating system is transferred from a secondary memory source, usually a hard disk to RAM. y The complete operating system contained in both ROM and RAM controls the computer. Courtesy of: The Computer Continuum

What Is an Operating System? z Earlier synonyms for the operating system: y monitor, supervisor, executive z Now, operating systems are referred to by their commercial names: y MS-DOS, Windows ‘ 98, Mac. OS, OS/2, UNIX, Linux, VMS, … Courtesy of: The Computer Continuum