intro to computer system

What is a SYSTEM ?

• A system is a combination of components working together.

What is a COMPUTER SYSTEM ?

• A computer system is a group of elements performing together to process data.

INPUT OUTPUTPROCESS

What is a COMPUTER ?

• A computer is a programmable electronic device that can store, retrieve, and process data.

Why do we USE computers ?• For convenience• Can process voluminous data

efficiently• More accurate (e.g.

calculations)• Increased productivity• Capable of routine &

dangerous tasks• Faster, thus saves TIME

Where are computers used?

• Business industry – financial management

• Hospitals – document management

• Educational Institutions – student records database management

CATEGORIES OF COMPUTERMAINFRAME• started its implementation during 1940s• were number-crunching machines that took up whole building and cost huge sums of money.• requires highly skilled people to operate

MAINFRAME

MINICOMPUTER

• closet-sized• enabled multiple simultaneous

users to access an expanded range of applications and

did so at a substantially reduced size, complexity and price compared to mainframe computers.

MINICOMPUTER

Informatics Computer Institute

MICROCOMPUTER

• fitted on a desktop• can be use by one person at a

time, but could run many different types of applications

MICROCOMPUTER

The Three Major COMPONENTSCOMPONENTS:

• HARDWARE

• SOFTWARE

• PEOPLEWARE

HARDWARE• the tangible objects used with

programs in the computer system

• refers to the physical components of the computer system, like chips, disk drives, monitors, keyboards, printers, & ports.

CLASSIFICATIONS of HARDWARE•PERIPHERAL DEVICESPERIPHERAL DEVICES•CENTRAL PROCESSING CENTRAL PROCESSING

UNITUNIT•MASS STORAGE SYSTEMMASS STORAGE SYSTEM

PERIPHERAL DEVICES• Any external device attached to the central

portion of the computer.TYPES of PERIPHERAL DEVICES

• Input – used to put data into your computer. (e.g. keyboard & mouse)

• Output – used to display & generate information. (e.g. monitor & printer)

• Input/Output (I/O) – used for BOTH entering data into & extracting data from a computer. (e.g. touch screen)

Major Components of

Computer System

System Unit

- the box that contains the essence of the computer - contain the computer’s brain,

its short and long term memory and the wiring that links all the pieces together. Peripheral devices attach to it using special connectors, usually on the back of the box

System Unit–provides secure mountings for circuit boards & storage devices

–protects delicate circuitry from the outside

–protects you from interference & dangerous voltage

System Unit

Keyboard

- the typewriter component of a PC. It enables you to enter

letters, numbers, and special characters into the computer.

Keyboard

Mouse - a primary input device on a modern computer. It enables you to interact with images on the monitor screen by controlling an on-screen icon called a cursor.

Monitor

- the computer’s primary output

device. Over the years, monitors have progressed from

small, black screens with crudely formed glowing green

or orange characters to large, flat-panel screens that display photographic-quality images in over 4 billion colors.

Monitor

Speakers

- provide the audio output for your system. The first PC speaker systems often consisted of two rather cheap speakers, but today’s computer sound

systems may have up to six speakers, including a subwoofer.

Speakers

Internal Components of a Personal Computer

Central Processing Unit (CPU)

• that part of the computer that performs calculations and controls the other parts of the computer.

•is an integrated circuit, contains I/O bus driver, ALU (arithmetic logic unit), registers, & an instruction decoder or control unit to direct the operation of other parts.

Central Processing Unit (CPU)

•MOTHERBOARD– is the printed circuit board in the computer that holds the microprocessor, expansion slots, additional processor chips, & wires that compose the bus.

• MOTHERBOARD

•MEMORY– is the internal storage area in the computer.

- Measured in megabytes (MB) for most PCs or gigabytes (GB) for high-end systems.

MEMORYMEMORY• RANDOM-

ACCESS MEMORY (RAM)– also considered as

the main memory– can BOTH write

and read into it– is volatile; thus,

dependent on electricity to maintain its contents.

• READ-ONLY MEMORY (ROM)– is the type of

memory which permits you to read data only.

– thus, cannot be written to

– e.g. contains instructions for starting up PC

MEMORYMEMORY

MEMORY TYPESMEMORY TYPES

SDRAMSDRAM , which is short for Synchronous DRAM is a type of DRAM that runs in synchronization with the

memory bus.

MEMORY TYPESMEMORY TYPESDDR RAM

DDR RAM, which stands for Double Data Rate, which is a type of SDRAM and appeared first on the market around 2001 but didn’t catch on until about 2001 when the mainstream motherboards started supporting it.

MEMORY TYPESMEMORY TYPES

DDR RAM

• CO-PROCESSORS– is an integrated circuit which holds

additional computer processing units which handle specific tasks in conjunction with the CPU.

– e.g. MATH CO-PROCESSOR, GRAPHICS CO-PROCESSOR, COMPRESSION CO-PROCESSOR

• CO-PROCESSORS

• EXPANSION SLOTS– are portals that allow new signals to

enter the computer & directly read its circuitry.

– any device that snaps into an expansion slot is known generically as an expansion card.

– e.g. VIDEO ADAPTERS, JOYSTICK ADAPTERS, etc.

• EXPANSION SLOTS

• BASIC INPUT/OUTPUT SYSTEM (BIOS)

–set of programs used by the operating system & application programs to activate hardware.

• BASIC INPUT/OUTPUT SYSTEM (BIOS)

• POWER SUPPLY– aims at regulation, maintaining the

voltage as close as possible to the ideal that’s desired by the circuits inside your PC.

- As it operates, the power supply of your PC attempts to make the direct current that’s supplied to your computer as pure as possible, as close to the ideal DC power as produced by batteries.

• POWER SUPPLY

• PORTS– enables the flow of information, into and out of a

computer.

MASS STORAGE SYSTEMS• FLOPPY DISKS

– is the premier data exchange medium for computers & most popular back up system.

720KB, 1.44MB, 2.88MB3 ½ ”

160KB, 180KB, 320KB, 360KB, 1.2MB

5 ¼ ”

CAPACITYDISK

• FLOPPY DISKS

• HARD DISKS – is the principal mass storage system in

most computers– holds all of your programs & data/files– no other peripheral device can approach

the usefulness of hard disks in terms of speed, capacity, & straightforward user installation.

• HARD DISKS

•TAPE–magnetically coated strip of plastic on which data can be encoded.

–similar to music cassette tapes

• TAPE

• OPTICAL STORAGE– promises unique mixture of

performance, removable cartridges, & high capacities.

Write Once Read ManyWORM

Compact Disc – Read-Only Memory

CD-ROM

Two Basic Optical-Based Storage System

• OPTICAL STORAGE

SOFTWARE• is a computer program• pure information • may be downloaded using phone lines• may be temporarily stored in a physical medium

(e.g. diskette, hard disk, etc.)

Classification of Software:SYSTEM SOFTWARE

APPLICATION SOFTWARE

PROGRAMMING LANGUAGES

SYSTEM SOFTWARESYSTEM SOFTWARE• controls the application processing and

hardware resources such as memory, disk space, & peripheral devices.

Norton, PC Tools, Anti-Virus, Editor, Disk Scanner, Debugger

Utilities

DOS, OS/2, Windows 95 & 98, Windows NT, UNIX, Novell

Operating System

ExamplesCategory

APPLICATION SOFTWAREAPPLICATION SOFTWARE

• created to assist users with a specific task• some of the popular applications:

– perform word processing– manipulate spreadsheets– manage database– communicate with other computers

Application SoftwareCategory Examples

Word processor Word, WordStar, WordPerfect, Ami-Pro

Spreadsheet Lotus 123, Excel, Quattro

Database Mgt. SystemDbase, FoxPro, FoxBASE, Access, Paradox

Graphics Harvard, AutoCAD, 3D Studio, Corel

Desktop Publisher PageMaker, Ventura, Publisher

Games Chess master, DOOM, Basketball

Educational MathCAD

Accounting Package ACCPAC, DAC-Easy

PROGRAMMING PROGRAMMING LANGUAGESLANGUAGES

• is nothing more than a list of instructions used to compose a step-by-step algorithm, the computer program.

• a recipe for a microprocessor or the step-by-step instructions in a how-to manual.

• representation of the instructions in human-recognizable form

PEOPLEWARE

EDP/MIS/ITS Manager, Project manager

Manager

Database Administrator, Network Administrator

Administrator

Programmer Analyst, System Analyst

Analyst

Database Programmer, System Programmer, Application Programmer, Game Programmer

Programmer

Data EncoderEncoder

Computer TechnicianTechnician

Examples of IT CareersCategory

PC Start-up Sequence

• When you turn on your PC, it starts itself automatically. All modern computers can boot themselves. They are built to run a permanently installed programs as the very first thing when “waking up”. That program usually is designed to load an operating system, but first it can do a number of useful tests.

PC START-UP SEQUENCE

• POST (Power On Self Test)– is the first program executed when a PC is

turned on or reset

• MS-DOS• WINDOWS XP

– Windows-based components start to load– an automatic process with Windows XP– device drivers & OS components loaded– Windows desktop is then initialized

BOOT & REBOOT PROCEDURE

• WARM REBOOTCtrl Alt Del

• COLD REBOOT– turn off your PC, wait for at least 5

seconds before turning it on again.

• BOOT– the process of turning the power on

for your PC to start up.

INTRODUCTION TO

COMPUTER NETWORK

• is an arrangement in which two or more computers are connected so that they can share data or peripheral devices, or both.

• can contain a few or up to hundreds of nodes (computer units).

Reasons to Networking• Peripheral Sharing

– multiple users can access same printer, modem, scanner, etc.

• File Sharing– files can be shared among different types of

computers.

• Security– sensitive data can be kept centrally and

accessed only by users with the proper authority.

LAN, MAN, & WAN

• Local Area Network (LAN)• It is a local area network is a data

communications network spanning a limited geographical area, a few miles at most.

A LAN is made up of the following:

• FILE SERVER

• A powerful computer with a large hard disk and a lot of memory. Its job is to store the network’s programs and data files, to handle requests for peripheral sharing, to respond to requests from users and to generally mediate network traffic and operations.

• WORKSTATIONS or CLIENTS

• NETWORK INTERFACE CARDS

• CABLE

• NETWORK SOFTWARE

• OPERATING SYSTEM SOFTWARE

• WORKSTATIONS or CLIENTS

• Computers of lesser capacity that are depend on the file server.

• NETWORK INTERFACE CARDS

• To connect the PC to the cables.

• CABLE

• To connect the computers.

• NETWORK SOFTWARE

• To connect the user and the network.

• OPERATING SYSTEM SOFTWARE

• To service user’s needs for resources like files and printers.

LAN, MAN, & WAN• Metropolitan Area Network (MAN)

• Once a network spans more than a few miles or campus environment, or such as city.

• Wide Area Network (WAN)• Brings companies into the sphere of

networking by connecting computers in the entire enterprise, which may span over several cities, states and countries.

E-MAIL & E-MAIL ADDRESS

• E-MAIL (Electronic Mail)

– is a method used to send & receive messages over a network

– use an e-mail program to compose & send a message, & it is sent to a remote mailbox, where it can be retrieved and read by the addressee.

• E-MAIL ADDRESS

– is the location where email messages can be sent to a user.

– consists of a username & an internet address, separated by an @ sign.

– e.g. jparas@informatics.edu.ph

INTERNET

• is called the network of networks• largest collection of interconnected

computer networks in the world

• connected through an ISP (Internet Service Provider)

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