COMPUTER SYSTEM CONCEPTS

Presented by:Dr. Akhlas AhmedPreston University

WHAT IS A COMPUTER? An electronic device, operating under

the control of instructions stored in its own memory unit, that can accept data (input), manipulate the data according to specified rules (process), produce information (output) from the processing, and store the results for future use.

Primary Storage Unit

Arithmetic and Logic Unit

Input Data Output Data

Secondary

Storage Unit

Central Processing Unit (CPU)

Control Unit

Registers

Any hardware component that allows you to enter data, programs, commands, and user responses into a computer

Includes – Keyboard

Mouse Optical Scanner

Touch Screen, so on

INPUT DEVICES

The processor, also called the central processing unit (CPU), has subdivided into two major subunits -

• The control unit interprets the instructions

• The arithmetic/logic unit (ALU) performs the logical and arithmetic processes

THE CENTRAL PROCESSING UNIT

(CPU)

OUTPUT DEVICES

Converts the electronic information produced by the processor into human-intelligible form for presentation to end users.

Includes – Video Display Unit

PrinterAudio Response Unit

STORAGE DEVICESStores data and software instructions needed

for processing.

Primary Storage Unit – RAM & ROM

Secondary Storage Unit –

Floppy disk, or disketteCompact Disc CD-R, CD-RW, CD-ROMDVDs – DVD-ROM, DVD-R, DVD-RW, DVD-RAMFlash disk/USB driveHard disk ( non removable)

Cache Memory for high speed – Storage circuitry stores

temporary instructions and data elements

1. TYPES OF COMPUTER SYSTEMS

• Microcomputer systems

• Personal computers, PDA’s, workstations etc.

• Midrange systems

• Network or Web servers, Multi-user systems etc.

• Mainframe systems

• Enterprise systems, Super servers, Transaction Processors etc.

COMPUTER HARDWARE

2. PERIPHERALS

•Monitors

•Printers

•Scanners

•Hard Disk Drives

•CD & DVD (Dissociated Vertical Deviation) Drives

•Backup Systems

3. INPUT TECHNOLOGIES

•Pointing Devices

•Pen based Computing

•Speech Recognition System

•Optical scanning

•Magnetic stripe

•Smart Cards

4. OUTPUT TECHNOLOGIES

•Video Output

•Printed Output

•Storage

• Magnetic Disks

• Floppy disks

• Hard disk drives

• Magnetic Tape

• Optical Disks

COMPUTER SOFTWARE Is the general term for various kinds of programs used to operate and manipulate computers and their peripheral devices.

TYPES OF SOFTWARE

•Application Software: performs information processing tasks for end

users.

• General purpose application programs

• Application specific programs (custom software)

•System Software: manages and supports operations of computer

systems and networks.

• System management programs.

• System development programs.

Business application software

Software suites

Web browsers

Electronic mail & Instant messaging

Word processing

DTP (Desktop Publishing)

Electronic spreadsheets

Presentation graphics

Personal information managers

Groupware

Application Software

System software

System management programs: Programs that manage the hardware,

software, network and data resources of computer systems during the

execution of information processing jobs of the user.

E.g. Operating system, DBMS etc.

System development program: Programs that help users develop

information system programs and procedures and prepare user programs

for computer processing.

E.g. Programming language translators & editors,

CASE (computer aided software engineering)

Computer software

Application software

General purpose

application programs

Application-specific

programs

System software

System development programs

System manageme

nt programs

Word processor, CRM, ERP, CASE packages, OS, DBMS, Spreadsheet E- commerce Programming Application Web browsers editors & tools servers

Performs information processing

tasks for end users

Manages & supports

operations of computer systems

and networks

THANK YOU